Cluster headache is associated with an increased risk of depression: A nationwide population-based cohort study

Objective: To investigate whether cluster headache (CH) was a risk factor for depression in a nationwide population-based follow-up study. Background: There are few studies about the relationship between CH and depression, and prior research has been limited by cross-sectional studies or small sample sizes. Methods: We identified 673 CH patients from the Taiwan National Health Insurance database between 2005 and 2009. The two comparison cohorts included age-, sex- and Charlsons score-matched migraine patients (n=2692) and controls (patients free from migraine or CH, n=2692). The cumulative incidence of depression was compared among these three cohorts until the end of 2009. We also calculated predictors of depression in the CH cohort. Results: After the median 2.5-year follow-up duration, the CH cohort had a greater risk for developing depression compared to the control cohort (adjusted hazard ratio; aHR=5.6, 95% CI 3.0-10.6, p<0.001) but not the migraine cohort (aHR=1.1, 95% CI 0.7-1.7, p=0.77). Of the CH patients, the number of cluster bout periods per year was a risk factor for depression (aHR=3.8, 95% CI 2.6-5.4, p<0.001). Conclusion: Our results showed that CH is associated with an increased risk for depression. The strength of this association is similar to that of migraine.